Projectile



Wu 9, m. G. A. MILLER, JR

PROJECTILE Filed Aug. 18 1939 Patented Nov. 9, 1948 PROJECTILE I GeorgeA. Miller, Jr., Weirsdale, Fla., assignor to the United States ofAmerica as the Secretary of War represented by Application August 18,1939, Serial No. 290,780

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) 6 Claims.

of safety features may be readily applied to fuses.

of artillery projectiles but their incorporation in small caliberprojectiles is not feasible.

The purpose of this invention is to provide a safety device for a fusewhich is so arranged and constructed that it may be practicably appliedto a small-caliber projectile. This purpose is accomplished by providinga barrier for a fuse element which will render the fuse inoperative orsafe until the projectile is in flight. The barrier or the membercontrolling the barrier is adapted to be rendered inoperative or removedor placed in a condition to be removed through the action of heatimparted by the gases of the propellent charge, by the passage throughthe bore of the '1 gun barrel and by the passage through the atmosphere.More specifically the barrier or the barrier controlling member consistsof a fusible alloy whose physical character is altered so that theinfluence of centrifugal force may be employed in arming the fuse.

The specific nature of the invention as well as other objects andadvantages thereof will clearly 2 collar l2 and the front face of thebody and surrounding the striker normally maintains the point of thestriker in spaced relation to the primer charge. The barrier memberpossesses such characteristics that normally it will have sufficientrigidity to hold the striker against movement but it is capable oflosing its rigidity during flight so that on impact the striker will bedriven rearwardly to fire the primer charge. This change in the physicalcharacter of the barrier is accomplished through the action of heatwhich is imparted by the propellant charge and/or by the passage of theprojectile through the bore of a gun barrel and its flight in the air.

The barrier may be formed of a combustible material or it may comprise afusible material consisting of an alloy composed of lead 26 parts, tin13 parts, cadmium 10 parts and bismuth 51 parts. This alloy has amelting point of approximately 180 F. Other elements may be substitutedfor those mentioned and alloys having higher or lower melting points maybe used.

In Fig. 1 the barrier is in the form of a hollow cylinder of a fusiblealloy and the height and diameter are such that an ordinary blow on theend of the striker will not reduce the height of the cylindersufficiently to permit the point of the striker to explode the primer.When the barrier has been softened through the application of heat amuch lighter blow will sufiice to move the striker inwardly, the strikereither penetrating the barrier or punching it out. When appear from adescription of a preferred embodiment as shown in the accompanyingdrawings in which:

Fig. 1 is a fragmentary longitudinal sectional .view of a fuse equippedwith the'improved bar-' rier.

Figs. 2, 4, 6, "I, 8, 9 and 10 are similar views showing modificationsofthe barrier.

Figs. 3 and 5 are sectional views on the respective lines of Figs. 2 and4.

Referring to Fig. 1 there is shown the front part of a projectile body 5which is formed with a chamber 6 for receiving a charge such as anexplosive, gas, or incendiary material. 1 at the forward end of thechamber receives a cup 8 containing a primer charge 9. A passage It)extends from the primer charge to the-front face of the body andreceives the inner end of a firing pin or striker II which protrudes anappreciable distance and is formed with a collar I2.

A barrier member 13 interposed between the A cavity sufficient heat hasbeen applied to melt the barrier it will be moved from around thestriker under the influence of centrifugal force due to rotation of theprojectile and in this event an extremely sensitive firing mechanism isprovided.

Any suitable and known means for holding the striker against forwarddisplacement may be provided.

In Figs. 2 and 3 the barrier 14 consists of a plurality of segmentsformed of a material such as brass having greater resistance tocompression than the fusible alloy. The segments are held together bythe soldering effect of a fusible alloy 15 disposed between adjoiningfaces of the segments. When the alloy is softened or melted the segmentsare thrown radially outward under the influence of centrifugal force.

In Figs. 4 and 5 the barrier I 6 is similar to that of Fig. 2 and itssegments are embraced by a sleeve ll of fusible alloy which functions asdescribed above.

In Fig. 6 a barrier l8 of a fusible alloy is interposed between thepoint of the striker l9 and a 3 primer 2D. The protruding head of thestriker is enclosed in and confined by a false ogive or cap 21 mountedon the body 22. The cap is readily crushed on impact and serves as awindshield during flight. The primer is carried in a block 23 which maybe either fixed or movable and is held in spaced relation to the body bymeans of the barrier. Where the block is in the form of a plunger it maymove forwardly on impact under the influence of inertia when the barrieris removed.

In Fig. 7 the structure and arrangement is similar to that shown in Fig.6 but the striker 24 is held intermediate its ends by means of aplurality of pins or bolts 25 which are slidably mounted in radiallydisposed passages 26 in the body 21. The inner ends of the bolts arenormally disposed in a recess or aperture 28 in the striker and they aremaintained in holding position by means of plugs 29-49 of a fusiblealloy which close the outer ends of the passages 26.

When the plugs are melted the bolts move outwardly under the influenceof centrifugal force to release the striker.

In Fig. 8 the arrangement is similar to that shown in Figs. 6 and 7 butthe striker 30 is held by a c lindrical barrier 3| of a fusible alloy asshown in Fig. 1. The protruding end of the striker is housed within acrushable cap 32 attached to the body 33.

In Fig. 9 a barrier 34 is arranged to normally interrupt a flash passage35 leading from the primer 36 to the explosive charge and constitutingan element of an ignition train. The barrier is releasably held by aplug 31 of a fusible alloy in the manner shown in Fig. 7.

In Fig. 10 a closure 38 for a container 39 serves to normally protect anexplosive or chemical compound 40 from exposure to the atmosphere. Asillustrations of the application to a projectile the closure may be atthe rear of the projectile to normall protect a tracer, signalling orincendiary composition. Furthermore since the barrier has beenillustrated as a safety member for various elements of a fuse the termelement of an ignition train as used in the claims is to be broadlyinterpreted.

In the event that a projectile equipped with the barrier fails to befired it may be removed from a heated barrel with safety because thefusible element of the barrier will resolidify.

I claim:

1. In combination with a rotatable projectile includ ng a body and anignition train having a firing element disposed partially externally ofthe body, a barrier disposed externally of the body for maintaining saidelement of the ignition train inoperative, said barrier comprising analloy fused by heat on discharge of the projectile from a gun to permitthe operation of the firing element.

2. In combination with a rotatable projectile including a body and anignition train having a firing element disposed partially externally ofthe body, a barrier of fusible material disposed externally of the bodyfor maintaining said element of the ignition train inoperative, saidbarrier fused by heat on discharge of th projectile from a gun.

3. In a projectile, a body, a firing element of an ignition trainprotruding from the body and mounted for movement therein, a cap on thebody for confining the protruding end of said element, and a barriermember of fusible material within the body symmetrically disposed aboutsaid firing element for normally opposing inward movement of saidelement, said barrier adapted to be fused by heat on discharge of theprojectile from a gun. said barrier in its fused state becominginoperative to oppose inward movement of said element.

4. In a projectile, a body, a movably mounted element of an ignitiontrain protruding from the body, and a cylindrical barrier of a fusiblealloy surrounding said element and confined between the element and thebody to hold the element against inward movement, said barrier fused byheat on discharge of the projectile from a. gun to permit operation ofsaid movably mounted element.

5. In a rotatable projectile, a body, a movably mounted element of anignition train in the body, a segmental barrier surrounding said elementand in cooperation with said body holding the element against movement,a fusible alloy, between adjoining faces of the segments and cementingthe segments together, said allo fused by heat on discharge of theprojectile from a un whereby the segments may be removed under theinfluence of centrifugal force incident to rotation of the projectile.

6. In a rotatable projectile, a body, a movably mounted element of anignition train in the body. a segmental barrier surrounding said elementand in cooperation with said body holding the element against movement,a fusible material between adjoining faces of the segments and cementingthe segments together, said material fused by heat on discharge of theprojectile from a gun whereby the segments may be removed under theinfluence of centrifugal force incident to rotation of the projectile.

GEORGE A. MILLER, JR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 253,649 Watson Feb. 14, 18821,172,637 Sample Feb. 22, 1916 1,216,834 Mo-ren Feb. '20, 1917 1,459,600Newton June 19, 1923 FOREIGN PATENTS Number Country Date 2,184 GreatBritain 1885 8,137 Great Britain 1885 216,539 Great Britain Nov. 26,1725 241,941 Great Britain Nov. 26, 1925 (10 245,766 Great Britain Jan.4, 1926 304,258 Germany May 27, 1920 349,839 Great Britain June 4, 1931

